The immediate goal of this project is to establish high titered scrapie infected tissue culture cell lines. Scrapie is a naturally occurring spongiform encephalopathy of sheep and goats which causes clinical and pathological changes similar to those of Creutzfeldt-Jakob and Kuru diseases of man. Scrapie grows to high titer in mouse lymphoid tissue and brain but has never been passaged at high titer in any in vitro system. Adaptation of the agent to cell culture will permit detailed characterization of the agent(s) and provide a system for better definition of the pathogenesis of these diseases. We have utilized two approaches designed to provide infected in vitro cell lines. In one approach, scrapie infected mice are injected with one of several splenotropic tumor cell lines. Once tumors are established in vivo, they are explanted, maintained in vitro and assayed for the presence of scrapie agent. The second approach utilizes hybridoma technology. Spleen cells from scrapie infected mice are fused with a myeloma cell line. If a scrapie infected cell was a partner in the fusion, persistently infected lines might result. Due to the long incubation period of scrapie in mice (greater than 4 months), results of these recent experiments are not available.